A biosensor may be denoted as a device which may be used for the detection of an analyte that combines a biological component with a physiochemical or physical detector component.
For instance, a biosensor may be based on the phenomenon that capture molecules immobilized on a surface of a biosensor may selectively hybridize with target molecules in a fluidic sample, for instance when an antibody-binding fragment of an antibody or the sequence of a DNA single strand as a capture molecule fits to a corresponding sequence or structure of a target molecule. When such hybridization or sensor events occur at the sensor surface, this may change the electrical properties of the surface which can be detected as the sensor event.
US 2004/0110277 discloses a bio-sensor comprising a sensor cell matrix in which sensor cells are arranged into a matrix, a row driver which supplies a specific voltage signal to a group of sensor cells lined up in the row direction of the matrix, and a column driver which supplies a specific voltage signal to a group of sensor cells lined up in the column direction of the matrix. Each sensor cell comprises a capacitance element consisting of a pair of opposing electrodes with probe DNA molecules that react selectively with target DNA molecules immobilized to their surfaces, a transistor whose gate terminal is connected to the capacitance element so that the current value that is output from the drain terminal of this transistor is caused to vary in accordance with the amount of the capacitance variation of the capacitance element which is varied by the hybridization of the DNA, and a switching element which supplies a voltage signal supplied from the column driver to the current input terminal of the transistor.
Conventional sensor chips may suffer from a signal to noise ratio which may be too small.